Indoor smd led equipped for outdoor usage

ABSTRACT

An SMD LED that is designed for indoor use is equipped for outdoor use by encapsulation in a vacuum-forming and/or cover molding covering, which is placed over the indoor SMD LED and is formed thereon by evacuation. The thus-equipped indoor SMD LED is thereby usable in the same manner as a more expensive and ruggedly designed outdoor SMD LED.

CROSS-REFERENCE TO RELATED APPLICATIONS

This utility application claims priority to and the benefit of U.S.Patent Application No. 62/077,044, filed Nov. 7, 2014, which is herebyincorporated by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to SMD (Surface Mount Device) LED (LightEmitting Diode) of the type originally designed for indoor usage, butspecially equipped for outdoor usage.

BACKGROUND OF THE INVENTION

As is well known, a light emitting diode (LED) is a solid-statesemiconductor component that, when supplied with an appropriate electriccurrent, emits light. LEDs are well known to have a high efficiency anda long life, which has resulted in an increasingly large number ofapplications for LEDs wherein traditional incandescent bulbs werepreviously used.

SMD LEDs are composed of a large number of individual LEDs that aremounted on the surface of a circuit board. The circuit board istypically a printed circuit board, which is flat and is also used, inaddition to mounting the LEDs, to appropriately electrically connect theLEDs. The printed circuit board may also have auxiliary components thatare used to drive the LEDs, but it is also possible for the LED drivingcircuitry to be separately (remotely) mounted.

By contrast, traditionally mounted LEDs have wire leads that connectthem to a circuit board. Typically, SMDs forego such wire leads, makingthe entire package compact.

SMD LEDs can be generally categorized into the categories of devicesdesigned for indoor use and devices designed for outdoor use. A typicaloutdoor use for such devices is to serve as a video display. In order towithstand the environmental factors that can impair or damage theoperation of such an outdoor device, outdoor SMD LEDs typically aredesigned with heavier and stronger components than an indoor SMD LED,which makes outdoor SMD LEDs more expensive. The outdoor environmentthat an outdoor SMD LED must be able to withstand can include water, UV,dust and other performance-degrading or material-degrading contaminants.

Attempts have been made to package or otherwise protect SMD LEDs designfor indoor use so as to make such indoor SMD LEDs suitable for outdooruse, in order to take advantage of the lower cost of indoor SMD LEDs.Once such approach has been to provide a transparent cover over theentirety of an indoor SMD LED product. A disadvantage of this approachis that many crack or other opening in such a cover comprises theintegrity of the entire device, by allowing water, for example, to reachthe interior of the covering, and it is difficult to ensure that suchcracks or openings will not develop in the covering much earlier thanthe expected usage life of the product. In other words, the durationthat such a covering can be expected to remain intact is less that theusually-expected duration of use of the outdoor SMD LED product.Moreover, in view of the complete seal that is needed, heat thatdevelops during usage of the SMD LED is difficult to release, and thecontinued use of the SMD LED in such an elevated temperature environmentshortens the life of the SMD LED.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to provide improved outdoor SMDLEDs that overcome the aforementioned disadvantages of SMD LEDs.

In a first aspect, an outdoor SMD LED comprising an indoor SMD LED; anda covering held in place over said indoor SMD LED by evacuation betweensaid covering and said SMD LED.

In a further aspect, said covering is a vacuum-forming covering or acover molding covering.

In a further aspect, said covering is made of plastic or silicone.

In a second aspect, an outdoor SMD LED display, comprising a printedcircuit board; a plurality of LEDs mounted to a same surface of saidcircuit board and forming, in combination with said circuit board, anindoor LED display; and a vacuum-forming and/or cover molding coveringplaced over said LEDs on said surface of said printed circuit board, andheld in place over said LEDs on said printed circuit board by evacuationof a volume between said covering and said LEDs on said circuit board,thereby forming a protection for said indoor LED display allowingoutdoor operation thereof.

In a further aspect, said vacuum-forming and/or cover molding coveringis made of plastic or silicone.

In a third aspect, a method for equipping an indoor SMD LED for outdooroperation, comprising providing an indoor SMD LED; and vacuum-formingand/or cover molding a cover on said indoor SMD LED, thereby protectingsaid indoor SMD LED for outdoor operation.

In a further aspect, wherein said cover is made of plastic or silicone.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures are for illustration purposes only and are not necessarilydrawn to scale. The invention itself, however, may best be understood byreference to the detailed description which follows when taken inconjunction with the accompanying drawings in which:

FIG. 1 shows an indoor SMD LED on a printed circuit board, in anembodiment forming a display.

FIG. 2 shows a vacuum-forming sheet used to cover the SMD LED display ofFIG. 1, in accordance with the invention.

FIG. 3 shows the vacuum-forming sheet in the process of covering thedevice of FIG. 1.

FIG. 4 shows a corner of the device of FIG. 1, covered by thevacuum-forming sheet.

FIG. 5 is a view showing the device of FIG. 1 covered by avacuum-forming sheet, in the process of evacuation, in accordance withthe present invention.

FIG. 6 is a second view showing the device of FIG. 1 completely coveredby a vacuum-forming sheet in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the invention, an SMD LED is encapsulated by avacuum-forming and/or cover molding sheet that is held in place byevacuation over the printed circuit board (PCB) to which the LED ismounted. In the example shown in FIG. 1, the device, in this case is anLED display 1, is shown before being covered by the vacuum-formingand/or cover molding sheet. The device shown in FIG. 1 is designed as anindoor device, meaning that, by itself, it would not be capable ofoutdoor use because it is not capable of withstanding an outdoorenvironment. The LED display 1 has multiple LEDs 3 on a PCB 2.

The sheet can be made of plastic, such as polycarbonate plastic,silicon, or the like. The sheet can be transparent or translucent, canbe in one or more colors, and/or can be embossed with one or morepatterns that can help direct light. The sheet can have at least oneanti-ultraviolet layer.

The sheet can be a vacuum-forming sheet, a cover molding sheet, or avacuum-forming and cover molding sheet.

Although the device shown in FIG. 1 is, as noted, configured as adisplay, the present invention can be used to equip any SMD LED that isdesigned for indoor use, so as to make the indoor use SMD LED able towithstand an outdoor environment, and thus usable as an outdoor SMD LED.

FIG. 2 shows a vacuum-forming and/or cover molding transparent sheet 4that is used to cover the device shown in FIG. 1, in accordance with theinvention. As can be seem from FIG. 2, the sheet is formed with a numberof recesses 5 that individually and respectively fit over each of theLEDs 3 on the PCB 2 in FIG. 1.

FIG. 3 shows the sheet 4 being pressed into place on the display 1 shownin FIG. 1. FIG. 4 shows the sheet completely covering the display shownin FIG. 1, but before evacuation.

FIG. 5 shows a view from above of the indoor SMD LED that is in theprocess of being equipped for outdoor use in accordance with theinvention by evacuating the volume between the sheet 4 and the display.As can be seen in FIG. 5, the volume at the lower left corner stillexists between the cover and the PCB with the LEDs as evacuationproceeds, in a known manner, so that the sheet 4 finally tightly coversand encloses the indoor SMD LED display 1, thereby completely protectingthe indoor SMD LEDs from the attacking factors that are typical in anoutdoor environment, and thereby producing a completed outdoor SMD LEDdisplay 5.

Although modifications and changes may be suggested by those skilled inthe art, it is the intention of the inventor to embody within the patentwarranted hereon all changes and modifications as reasonably andproperly come within the scope of his contribution to the art.

What is claimed is:
 1. An outdoor SMD LED comprising: an indoor SMD LED; and a covering held in place over said indoor SMD LED by evacuation between said covering and said SMD LED.
 2. The outdoor SMD LED of claim 1, wherein said covering is a vacuum-forming covering or a cover molding covering.
 3. The outdoor SMD LED of claim 2, where the covering is made of plastic or silicone.
 4. An outdoor SMD LED display, comprising: a printed circuit board; a plurality of LEDs mounted to a same surface of said circuit board and forming, in combination with said circuit board, an indoor LED display; and a vacuum-forming and/or cover molding covering placed over said LEDs on said surface of said printed circuit board, and held in place over said LEDs on said printed circuit board by evacuation of a volume between said covering and said LEDs on said circuit board, thereby forming a protection for said indoor LED display allowing outdoor operation thereof.
 5. The outdoor SMD LED display of claim 4, wherein said vacuum-forming and/or cover molding covering is made of plastic or silicone.
 6. A method for equipping an indoor SMD LED for outdoor operation, comprising: providing an indoor SMD LED; and vacuum-forming and/or cover molding a cover on said indoor SMD LED, thereby protecting said indoor SMD LED for outdoor operation.
 7. The method for equipping an indoor SMD LED for outdoor operation of claim 6, wherein said cover is made of plastic or silicone. 